Effective immobilization of silver nanoparticles on a regenerated cellulose–chitosan composite membrane and its antibacterial activity

Abstract

An antibacterial chitosan–cellulose composite membrane, containing silver nanoparticles (AgNPs), was fabricated by coagulating a cellulose solution in a chitosan solution, followed by the in situ synthesis of AgNPs on the produced membrane. By adjusting the concentration of chitosan (0–2.5%, w/v) in acetic acid coagulating solution, various cellulose–chitosan membranes with different chitosan contents were produced, which then served as substrates for the in situ synthesis and immobilization of AgNPs via a microwave-assisted approach. The amount of AgNPs deposited on the membrane was measured and found to increase with an increasing in the chitosan content on the membrane. Electron micrographs of the membranes revealed entanglement of chitosan on the membranes structure, whereas AgNPs were deposited on the membrane surfaces. In addition, the surface roughness of the membrane increased as a result of the increase of chitosan and AgNPs on the membrane surfaces. Consequently, the membranes exhibited an improved antibacterial activity against Staphylococcus aureus and Escherichia coli as the AgNPs content increased. In conclusion, this study demonstrated a successful green approach for preparing a nanocomposite membrane of cellulose–chitosan–AgNPs with strong antibacterial activities.